SWRevealViewController 无错误

SWRevealViewController nil error

我正在使用 SWRevealViewController

当我单击返回按钮时出现此错误

fatal error: unexpectedly found nil while unwrapping an Optional value

my code

let nesne:SWRevealViewController = self.revealViewController()//the error here
let mainStroyBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let desController = mainStroyBoard.instantiateViewController(withIdentifier: "MessageViewController") as! MessageViewController
let newFrontViewController = UINavigationController.init(rootViewController:desController)
nesne.pushFrontViewController(newFrontViewController, animated: true)

solution

let sw = storyboard?.instantiateViewController(withIdentifier: "SWRevealViewController") as! SWRevealViewController
self.view.window?.rootViewController = sw

let mainStroyBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let desController = mainStroyBoard.instantiateViewController(withIdentifier: "MessageViewController") as! MessageViewController
let newFrontViewController = UINavigationController.init(rootViewController:desController)
sw.pushFrontViewController(newFrontViewController, animated: true)